login
a(n) = Sum_{k=1..n} mu(k)^2 * ceiling(n/k), where mu is the Möbius function (A008683).
1

%I #4 Jan 01 2024 23:26:27

%S 1,3,6,8,11,14,19,21,23,26,31,33,38,41,46,50,53,55,60,62,67,72,77,79,

%T 83,86,90,92,97,100,109,111,114,119,124,128,133,136,141,145,150,153,

%U 162,164,168,173,178,180,184,186,191,195,200,202,207,211,216,221,226,228

%N a(n) = Sum_{k=1..n} mu(k)^2 * ceiling(n/k), where mu is the Möbius function (A008683).

%F a(n) = A013928(n) + A008966(n) + A064608(n) - A034444(n).

%t Table[Sum[MoebiusMu[k]^2*Ceiling[n/k], {k, n}], {n, 100}]

%Y Cf. A008683 (mu), A008966, A013928, A034444, A064608.

%K nonn,easy

%O 1,2

%A _Wesley Ivan Hurt_, Jan 01 2024